


two seibas and a caster

by MSAF



Category: Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: F/M, Face-Sitting, Femdom, M/M, Mind Control, Plot What Plot/Porn Without Plot, Threesome - F/M/M, if you havent guessed this is indulgent porn that doesnt make sense, non-con (kinda), please enjoy my degeneracy
Language: English
Status: Completed
Published: 2020-07-05
Updated: 2020-07-05
Packaged: 2021-03-05 00:29:03
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,271
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25085440
Author URL: https://archiveofourown.org/users/MSAF/pseuds/MSAF
Summary: Merlin and Musashi have been spending too much time together after summer, leaving Bedivere jealous and in want of Merlin's touch. There's a solution for that.
Relationships: Bedivere | Saber/Merlin | Caster, Bedivere | Saber/Merlin | Caster/Miyamoto Musashi | Saber, Merlin | Caster/Miyamoto Musashi | Saber
Comments: 1
Kudos: 3





	two seibas and a caster

**Author's Note:**

  * For [PartridgeOnAPearTree](https://archiveofourown.org/users/PartridgeOnAPearTree/gifts).



> HELLO I made this fic last year after contemplating musashi and merlin's r/s in the 2019 jp summer event! I'm not gonna go in-depth into character analyses or anything but they have a lot of lines (from events or in the story) that seem to show that they're both kinda (somewhat?) the same but they don't actually Like Each Other (tm) which points to a lot of self-loathing (which they also have, confirmed by in-game lines and story) and BASICALLY these two are great frenemy > lovers ship material
> 
> and so I decided to run with that and get them both to fuck bedivere because I love merbedi. and now I'm uploading my degeneracy on ao3 because the merbedi tag rly needs more fics AND I'd also like to dedicate this to my gorlf because Porn (tm)
> 
> I'd like to give special thanks to my gorlf who examined all those in-game lines from stories/events/my room and essentially figured out that Musashi/Merlin is a thing which Can Actually, Reasonably Exist (tm) and which led to the creation of this!!!!!!!!!! She's beautiful please read her works @PartridgeOnAPearTree !!!!!

“Come on, Bedi, spread those legs.”

“I can’t believe we’re actually doing it! Pretty boys are always at their best in bed!”

Bedivere can’t see anything.

More accurately, his vision is being obscured by what Master would describe as a ‘nice, thick ass’. He can’t feel much other than the dripping pussy on his lips, and he vaguely wonders if this is the punishment he gets for feeling so jealous of Musashi. Not that this is uncomfortable for him, but it’s so—

His thoughts get interrupted when he suddenly feels said pussy grinding against his lips and choking him.

“Come onnnn! I’m so horny! Did I kill you by accident or something?”

He lets out a groan and slowly licks at Musashi’s clit, eliciting a loud sigh from the swordsman. He hasn’t done this before, so he’ll have to do his best to please the swordsman. It’s a new experience—Just like when Merlin kissed him for the first time. He revels in the sensation and the heat, and lets his mind drift away without a concern in the world. Maybe he likes this—Being dominated. Maybe its just how he likes everything to be like. ‘Serving someone is natural to me,’ Merlin would say, but Bedivere would feel ecstatic if he could serve him too.

He feels his leg being parted, and a hot, warm hole engulfing his cock. He struggles to keep his mouth shut and moans while sucking gently onto her nib. Fuck, is that her mouth? Her mouth is so tight—

“Yes, there we go. Take him deeper. I hope you don’t mind, but I’ll be using him too.”

  
Ahh, that was Merlin, wasn’t it—

He lets out another loud moan as he feels penetration. So good, so good. He’s made love to Merlin many times, but never like this—Never with a third person in the middle, driving him insane as he desperately attempts to please her. It’s not like he’s been dreaming of this or anything, but it just felt so good—

They work into a steady rhythm, in that way—Musashi grinding herself against Bedivere’s mouth as she sucks his cock, Bedivere eating Musashi out as he lets himself get fucked, and Merlin thrusting into Bedivere while roughly tugging on Musashi’s hair. It felt amazing. The knight wonders if he’ll ever feel this sensation again, or if this is a one time event. A part of him, the shy and embarrassed part, hopes that this will only happen once—He simply won’t be able to look at Musashi in the same way ever again after all. But another part of him, a darker and needier part of him that had been coaxed into the open by Merlin, wanted much more. More of this pleasure, this debauchery, this sin. Couples should be making love only to each other, he thinks. It doesn’t matter the gender, but surely, they should keep an intimate act like sex to themselves. It’s an act of love. It’s not meant to be used for the fulfilment of lust.

And yet, and yet—

Bedivere wants to engulf himself deeper into this, wants to accept Musashi even just a little bit, so they can carry on their threesome. He’d been so jealous of Musashi beforehand, but now he just wants to fuck and get fucked by the two of them—His beloved mage, and the feisty swordsman. He can barely remember what it felt like to be jealous of her—Nothing as good as this, surely! So Bedivere should just, just accept this and—

His eyes snap open as though he woke up from a dream. Knowing Merlin, that description might not be inaccurate. He lets out an angry growl as he furiously laps at her vagina, a hand sneaking upwards to tease and play with her hole. He’s so stupid! _Of course_ Merlin would use a little bit of his incubus magic here. _Of course_ Merlin would try to make him feel okay with this. _Of course_ Merlin would be scummy enough to make his lover enjoy having a threesome with his _mistress_. He’s going to bully this—this—!! This brainless udon-eating bitch until he’s satisfied!

Bedivere can feel the way her throat vibrates around his cock when she moans and he lets out a moan too. It feels so good like that, when she deepthroats him and makes him feel all warm and tingly there—But he can’t accept that! He got forced into this, he thinks! He can’t remember how he got here, so he definitely got forced into this! He drags a finger in and out of Musashi, hoping to punish her as much as he can—The way she moans only further drives his roughness, not letting his fingers get wet to show how much he hated her.

He feels so angry right now. He’s never felt so angry in his whole life. All he knows is that he’s going to push this awful woman into a painful orgasm and get his revenge. Yes, that’s it. It’s perfect. He won’t let Merlin influence him any further. It’s time for him to show that he won’t snap, no matter what sort of magic Merlin uses to control him. He won’t bend or break or listen to any of his commands—Never!

Merlin lets out a grunt and Bedivere immediately feels his brain melt into jelly.

“Fuuuck, you’re tighter than usual…”

He feels a burst of happiness take over him, but—No, no! He can’t! That’s Merlin’s magic taking over him! He focuses all of his willpower into bullying Musashi, so that she can suffer the most humiliating orgasm of her life—

It goes on like this for a while, with Bedivere fingering Musashi and driving her closer and closer to cumming. Bedivere feels like he’s about to cum, too—While he wouldn’t admit it, she was really, really good at taking his dick, and Merlin was hitting all of his sweet spots. Before he could really process it, he was cumming while Musashi deepthroated him, and he could taste salt on the tip of his tongue—The awful woman was cumming too. He slurped it all up as she did, savouring the taste and the sense of accomplishment he felt. She groaned as she choked on his cock, and he felt a sense of victory, too—Finally, he managed to teach her where she belongs. He should have done this sooner. Musashi wouldn’t have flirted with his beloved mage everyday if he had just taught her where she stood all this time and—

Bedivere suddenly realises that he’s the one who lost as Merlin orgasms inside of him. He feels his belly filling with incubus cum and he shudders with need. Oh, _finally_ , finally he got the thing he needed the most—No, wait, hold on—

He groans as he realises that Merlin must have used an extra heavy dose of magic today, because suddenly all of his thoughts didn’t feel quite right—He never wanted to shove his cock deep into Musashi’s throat and choke her before today, for example—And he feels himself sink deeper into the bed.

He’s so tuckered out. He’s just going to… sleep for a bit…

It’s only after they had all fallen asleep that Musashi realised she was sleeping with her ass crushing Bedivere’s face the entire time—He had to get patched up for breathing issues afterwards.

Bedivere still hasn’t forgiven Merlin for the incident but doesn’t deny another session either.

Musashi is also not against going for another round, since she enjoyed the knight’s rough treatment.

The mage smiles.


End file.
